The U.S. Justice Department has opened a civil rights investigation into the beating of a 64-year-old black man in flood-ravaged New Orleans.

The probe announced Monday was launched following the release of a videotape showing two uniformed New Orleans police officers punching Robert Davis in the face and body as he was being arrested for public drunkenness.

Another officer is shown shoving and screaming at a news producer who was documenting the confrontation.

Mr. Davis says he does not drink alcohol and was just out looking for cigarettes. He told CNN television that the incident started after he called one of the police officers unprofessional for interrupting his talk with an officer on horseback.

Mr. Davis's attorney says his client does not believe race was a factor in the Saturday night incident.

The three white police officers seen in the video have pleaded not guilty to battery charges.